1. Field of the Invention
This invention relates to disk drive suspensions, and, more particularly, to suspension load beam designs that minimize second torsion gains through the aligning of the load beam side profile with the rotation centerline of the suspension.
2. Description of the Related Art
Shock performance, shock characteristic, or “shockability” of a suspension assembly may be defined as the maximum shock the suspension can be subjected to while the slider still maintains its pre-loaded configuration. It is inversely proportional to the ‘effective mass’ of the assembly. The effective mass of a suspension assembly (M) is the value of a point mass to be positioned at the free end of the suspension so that the moment it generates about the fixed end (mount plate) of the suspension is equivalent to net moment generated by the entire head-suspension assembly. The inverse of the suspension effective mass gives a measure of its shockability.
Methods to determine the ‘shockability’ of a head suspension assembly have included subjecting the assembly to a shock impulse of known magnitude and measuring the back flexing of the assembly, based on the observation that when an impulse is applied to the suspension mount plate, the free end that carries the head jerks backwards (the suspension is said to back flex) and then returns back to its undisturbed, original and normal position.
In this method, successive shock pulses with incrementally increased magnitudes are applied, and for each shock pulse the magnitude of back flexing of the suspension is recorded. A regression analysis on the pulse values and the back flex values provides a value of shock pulse that corresponds to zero back flexing of the suspension. This value is the shock characteristic or shockability of the suspension assembly.
This test method is prone to a number of uncontrolled variables as set out in the Detailed Description section below that preclude the greatest accuracy and reproducibility of result.